Professor Severus Snape teaches Potions in J.K. Rowling’s first Harry Potter novel.
In Harry Potter and the Philosopher’s Stone, Snape is introduced as the Hogwarts teacher responsible for Potions. The subject involves brewing magical mixtures from ingredients, following precise instructions, and understanding the effects of different substances.
Snape’s classroom is in the Hogwarts dungeons, and Harry quickly develops an antagonistic relationship with him. Snape appears biased against Harry and favors students from Slytherin, creating one of the first major adult-student tensions in the series.
Snape’s role changes over the course of the books. He later becomes the Defence Against the Dark Arts teacher for one school year and eventually serves as Hogwarts headmaster. His history with Harry’s parents and his connection to Lily Potter become central to the series’ larger revelations.